u.s. ties ahead of the withdrawal of international combat troops at the end of 2014. >> these are events that we are familiar with. we work very, very closely with our afghan partners. they events that affect both isef and our afghan security force brothers. we continue to work to mitigate them as much as possible. >> the taliban has not claimed responsibility for the shooting in kabul on monday. but the group claims to have placed many infiltrators in the afghan military and police forces to launch attacks on international troops. >>> an archaeological dig in afghanistan unearthed priceless cultural assets. the area is also home to a large copper deposit. researchers are concerned that historic artifacts may be destroyed. nhk world's hideki yui has the story. >> reporter: researchers have found a settlement in mes ayak. their dig site plays within the perimeters of a copper mine and the development of a chinese state owned company. in 2009 the afghan government suspended mining exploratio